Robertson Sarah E, Rysavy Matthew A, Blakely Martin L, Steingrimsson Jon A, Dahabreh Issa J
From the CAUSALab, Harvard T.H. Chan School of Public Health, Boston, MA.
Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA.
Epidemiology. 2025 Jun 5. doi: 10.1097/EDE.0000000000001875.
We discuss generalizability analyses under a partially nested trial design, where part of the trial is nested within a cohort of trial-eligible individuals, while the rest of the trial is not nested. This design arises, for example, when only some centers participating in a trial are able to collect data on nonrandomized individuals, or when data on nonrandomized individuals cannot be collected for the full duration of the trial. Our work is motivated by the Necrotizing Enterocolitis Surgery Trial, which compared initial laparotomy versus peritoneal drain for infants with necrotizing enterocolitis or spontaneous intestinal perforation. During the first phase of the study, data were collected from randomized individuals as well as consenting nonrandomized individuals; during the second phase of the study, however, data were only collected from randomized individuals, resulting in a partially nested trial design. We propose methods for generalizability analyses with partially nested trial designs. We describe identification conditions and propose estimators for causal estimands in the target population of all trial-eligible individuals, both randomized and nonrandomized, in the part of the data where the trial is nested while using trial information spanning both parts. We evaluate the estimators in a simulation study and provide an illustration using the Necrotizing Enterocolitis Surgery Trial study.
我们讨论部分嵌套试验设计下的可推广性分析，在该设计中，部分试验嵌套于符合试验条件的个体队列中，而试验的其余部分则不嵌套。例如，当参与试验的只有部分中心能够收集非随机个体的数据时，或者当在整个试验期间无法收集非随机个体的数据时，就会出现这种设计。我们的工作受到坏死性小肠结肠炎手术试验的推动，该试验比较了坏死性小肠结肠炎或自发性肠穿孔婴儿的初始剖腹手术与腹腔引流。在研究的第一阶段，从随机个体以及同意参与的非随机个体中收集数据；然而，在研究的第二阶段，仅从随机个体中收集数据，从而形成了部分嵌套试验设计。我们提出了部分嵌套试验设计的可推广性分析方法。我们描述了识别条件，并针对所有符合试验条件的个体（包括随机和非随机个体）在试验嵌套部分的数据中的目标总体中的因果估计量提出了估计方法，同时使用跨越两个部分的试验信息。我们在模拟研究中评估了这些估计量，并使用坏死性小肠结肠炎手术试验研究进行了说明。
